Journal of Arthropod-Borne Diseases

Impact of Omics Studies on Understanding Insecticide Resistance Mechanisms in Sub-Saharan Malaria Vectors: A Systematic Review

Sat, 06 Dec 2025 00:00:00 +0330

Background: Malaria remains a major global health challenge, disproportionately affecting sub-Saharan Africa. The growing threat of resistance to insecticides in Anopheles vector populations poses a major challenge to the efficacy of core interventions such as long-lasting insecticide-treated nets (LLINs) and indoor residual spraying (IRS). This systematic review aimed to evaluate the contribution of omics approaches, particularly genomics, transcriptomics, and multi-omics, to understanding the resistance mechanisms in malaria vectors in sub-Saharan Africa and their impact on current and future vector control strategies.
Methods: A comprehensive search was conducted using PubMed, Web of Science, and Google Scholar for eligible studies published between January 2016 and April 2025. Studies using at least one omics approach to investigate resistance in Anopheles species were included. We extracted and analyzed data on study location, vector species, omics methods, insecticide classes, resistance mechanisms, and key findings according to PRISMA guidelines.
Results: Twenty-two studies met the inclusion criteria. Genomic and transcriptomic approaches revealed key resistance mechanisms, notably involving metabolic resistance, target-site mutations, and cuticular changes. Multi-omics studies uncovered novel resistance markers such as CYP450 reductase (CPR), UDP-glycosyltransferases (UGTs), and salivary gland proteins. Multi-country collaborations were common, reflecting the cross-border nature of insecticide resistance, while species-specific responses highlighted localized adaptation.
Conclusion: Omics studies have significantly enhanced the understanding of resistance to insecticides among malaria vectors, offering valuable insights for molecular diagnostics and region-specific vector control. Integrating these approaches into routine surveillance is crucial to inform sustainable malaria control and elimination strategies.

The Association between Demodex Infestation and Hair Loss Severity in a Referred Patient Population

Sat, 13 Dec 2025 13:55:21 +0330

Background: Hair follicle mites of the genus Demodex (Prostigmata: Demodicidae) are the most common external obligate parasites in humans, which reside in the eyelids, sebaceous glands, and ear canal, and can cause clinical disease. The purpose of this study was to investigate the possible role of Demodex parasites in causing discomfort in patients referred to Tehran laboratories due to hair loss.
Methods: This cross-sectional study was conducted on 520 patients referred to a laboratory in Tehran, Iran, presenting with hair loss. Sampling was performed from the scalp and face, and samples were examined for Demodex mites using light microscopy.
Results: The results showed that among the 520 patients referred to the laboratory, 66.15% were infected with Demodex. Out of 344 positive cases, 83.43% were women and 16.57% were men. Among the affected patients aged between 7 and 70 years, most patients (59.01%) were in the age group of 25.4 to 39.2 years. A high prevalence of Demodex infestation (66.15%) was found among patients with hair loss.
Conclusion: Our findings establish a highly significant, direct correlation between the severity of hair loss and the density of Demodex mite infestation (p< 0.001). We propose that high Demodex mite density is a significant contributory factor in the etiology of severe hair loss.

Isolation and Diagnosis of Medically Significant Parasites from the American Cockroach (Periplaneta americana) in Shendi City, Sudan

Yassir Sulieman, Randa Eltayeb, Theerakamol Pengsakul — Tue, 23 Dec 2025 11:25:37 +0330

Background: Cockroaches are ubiquitous in residential environments and can act as vectors for pathogens relevant to public health. This investigation aimed to determine the diversity, prevalence, and intensity of parasites carried by the American cockroach, Periplaneta americana, in Shendi City, Sudan.
Methods: A total of 117 P. americana specimens were collected during the summer of 2021 from residential kitchens, bathrooms and sewers using jar traps baited with bread. Following euthanasia by freezing each cockroach was examined for external and internal parasite stages (cysts and ova) via standard parasitological techniques.
Results: The overall parasite prevalence was 31.6%, with a mean intensity of 6.7 parasites per infected insect. Eight species were detected: three protozoans (Entamoeba histolytica/dispar, Entamoeba coli, Giardia lamblia) and five helminths (Ascaris lumbricoides, Trichuris trichiura, Ancylostoma sp., Taenia sp., Enterobius vermicularis). Entamoeba coli was the most prevalent (10.3%), followed by E. histolytica/dispar (7.7%), T. trichiura and Ancylostoma sp. (0.9% each). Taenia Parasite prevalencesp. showed the highest infection intensity (8.6) compared to the lowest (4.0), E. vermicularis and T. trichiura. Statistically, the parasite prevalence and intensity were significantly greater on the cockroaches' body surfaces compared to their digestive tracts (P< 0.001). Adult cockroaches also demonstrated significantly higher infection rates and intensities than nymphs.
Conclusion: The findings confirm that the cockroach, P. americana, can serve as a mechanical vector for protozoan and helminth parasites. Implementing preventive strategies, including improved sanitation and comprehensive pest management, is crucial to reducing the associated public health threat.

Chemical Composition and Control Potential of Melia azedarach Extracts Against Culex pipiens

Wail Ismael Hassan, Abbas Ali Zamani, Yousif Dakeel Rashid, Arezoo Jamshidi — Tue, 23 Dec 2025 11:34:08 +0330

Background: Culex pipiens (Diptera: Culicidae) poses a persistent global health challenge. The overuse of synthetic insecticides has led to resistance and environmental damage, underscoring the need for sustainable alternatives. Melia azedarach (Meliaceae) represents a promising source of bioactive compounds. This study aimed to comprehensively evaluate the potential of alkaloid extracts from M. azedarach against all life stages of Cx. pipiens and to characterize their phytochemical composition.
Methods: Crude alkaloid extracts were prepared from both plant parts. Ovicidal, larvicidal, pupicidal and adult repellent effects, were assessed through laboratory bioassays. The chemical profile of the extracts was determined using Gas Chromatography-Mass Spectrometry (GC-MS).
Results: Bioassays demonstrated significant ovicidal activity, with 100% egg mortality at 1% (w/v) concentration. Larvicidal activity was also notable at 1% (w/v). The fruit extract caused 100% mortality across the first three larval instars, while the leaf extract caused 100% mortality in the first two instars and 96.6% in the third. In the fourth instar, larvae showed 93.33 and 91.67% mortality with the fruit and leaf extracts, respectively. The extracts exhibited significant repellent effects, with rates of 63.00% and 60.00% at 1% (w/v) and consistently negative equilibrium ratios. GC-MS analysis showed the fruit extract was rich in insecticidal fatty acid esters, while the leaf extract contained repellent terpenoids like Piperitenone Oxide. Linoleic acid was a major shared compound, potentially underpinning the broad-stage efficacy.
Conclusion: These findings support the use of M. azedarach extracts as a promising, locally accessible and environmentally responsible strategy for integrated Cx. pipiens mosquito management.

Molecular and Serological Evaluation of Hantavirus in Wild Rodents in Kohgiluyeh and Boyer-Ahmad Province, Southwest of Iran

Mon, 29 Dec 2025 00:56:03 +0330

Background: Hantaviruses are mainly transmitted to humans through the inhalation of aerosolized excreta from infected rodent reservoirs. The present study was conducted to analyze the prevalence of hantavirus infection among rodents in the Boyer-Ahmad region.
Methods: A total of 52 rodents were captured in the Boyer-Ahmad region of Kohgiluyeh and Boyer-Ahmad Province during June to November 2014, using Sherman live traps. Blood and tissue samples were obtained from the heart and lungs, respectively. Hantavirus Pool 1 "Eurasia" IgG and Pool 2 "America" ELISA IgG kits were used to detect IgG antibodies against both Old World and New World hantaviruses. Moreover, total RNA extraction was performed on the lung tissue, and a pan-hantavirus nested RT-PCR was conducted to detect hantavirus RNA.
Results: Meriones persicus was the most abundant species (n=25, 48%). The results of the ELISA showed that all the serum samples from the rodents were negative for antibodies against both Eurasian and American hantaviruses. Moreover, no rodent tissue samples tested positive for the hantavirus RNA by the pan-hantavirus RT-PCR.
Conclusion: Although no hantavirus infection was detected in this study, the presence of hantavirus reservoirs in Kohgiluyeh and Boyer-Ahmad Province suggests that hantavirus circulation cannot be completely ruled out. Further studies with a larger sample size are recommended.

Exploitation of Endemic Extremophilic Microbial Strains Isolated from Date Palm Fibrillium in the Saoura Region (Southwest Algeria) as Potential Biocontrol Agents against Mosquitoes

Boulanouar Ali, Larbi Benlarbi, Zineb Hamani — Tue, 06 Jan 2026 12:09:20 +0330

Background: Algeria’s extreme ecosystems, such as the Saoura region, represent unique reservoirs of rare microorganisms, inhabiting pristine and unexplored virgin territories with considerable biotechnological potential. Chitinolytic bacteria are particularly noteworthy for mosquito control due to their ability to degrade chitin, the major structural component of the insect cuticle. This study aims to: (i) identify new microbial strains adapted to extreme desert conditions, overcoming the limited efficacy of some bioinsecticides, (ii) address the spread of vector-borne diseases and mosquito resistance, (iii) reduce the environmental impacts of non-selective insecticides, and (iv) explore eco-friendly strategies and integrated biological control.
Methods: Shrimp chitin was extracted to prepare selective media for the isolation and purification of chitinolytic bacteria. The entomopathogenic activity of these chitinolytic strains at concentrations of 10⁴, 10⁵ and 10⁶ CFU/mL was evaluated through bioassays on Culex pipiens larvae.
Results: We isolated three chitinolytic strains from Phoenix dactylifera bark, among which Streptomyces spp. 2 (STR2) was clearly the most virulent against Cx. pipiens larvae. This strain exhibited marked dose and time-dependent toxicity (LC₅₀-LC₉₉: 7.9×10³-3.4×10⁷ CFU/mL; DC: 6.8×10⁷ CFU/mL; LT₅₀: 4.6 days). Beyond larval mortality, it also severely affected adults by reducing the proportion of flight-capable mosquitoes and increasing rates of flightlessness, post-emergence mortality, and deformity. However, an IGR-like mode of action remains speculative.
Conclusion: This study confirms the larvicidal activity of desert-adapted chitinolytic bacteria, but further research is needed to determine their selectivity toward non-target organisms before considering their application in mosquito management.

Insecticidal Activity of Salvia officinalis, Pistacia vera and Eucalyptus sp. Extracts Against Phlebotomus papatasi: A Potential Plant-Based Approach for Vector Control

Azadeh Asadi, Mohammad Saaid Dayer, Amrollah Azarm — Mon, 19 Jan 2026 11:37:24 +0330

Background: Insecticides are essential for controlling Leishmania vectors, but their extensive use leads to adverse environmental effects, particularly on non-target species. Given the health challenges associated with synthetic insecticides and the dire need for safe and sustainable alternatives, plant-based insecticides offer a promising solution. This study explores the insecticidal potential of Salvia officinalis, Pistacia vera and Eucalyptus sp. as environmentally friendly alternatives for controlling Phlebotomus papatasi.
Methods: Methanolic extracts of S. officinalis, P. vera and Eucalyptus sp. were prepared using the maceration method. The extracts were analyzed using titration methods for bioactive compounds, including flavonoids, alkaloids, tannins, saponins and antioxidant properties. Susceptibility tests on Ph. papatasi were performed using WHO standard kits, with median lethal time (LT₅₀) and median lethal dose (LD₅₀) values calculated by probit analysis.
Results: Phytochemical analysis revealed the presence of flavonoids in S. officinalis and Eucalyptus sp. None of the extracts contained alkaloids, but all contained tannins. Pistacia vera was the only extract containing saponins. The LD₅₀ values after 24 hrs for S. officinalis, Eucalyptus sp. and P. vera were 0.156, 0.576 and 0.41 μg/ml, respectively. The LT₅₀ values for S. officinalis, Eucalyptus sp. and P. vera at 1.6 μg/mL were 11.9, 12.5 and 14.4 hrs, respectively.
Conclusion: Plant-derived insecticides are gaining attention due to their potential to mitigate the environmental and health risks posed by synthetic insecticides. The findings suggest that S. officinalis, P. vera and Eucalyptus sp. extracts may serve as effective biopesticides, contributing to integrated vector management strategies for leishmaniasis control.